“Losing a loved one in a preventable way compounds your grief and your devastation,” her mother told Today.
“But if nobody learns from it, nothing changes.”
Campaigning for Martha’s Rule had been “exhausting” but seeing people willing to learn from mistakes had helped her and her husband.
“There were definitely sceptics” at the scheme’s launch, in April, Ms Mills said.
She told Today: “There were people who said if you give patients this kind of power, they’ll call it for the wrong reasons – they will be complaining about food, they’ll be wanting a cup of tea.
“And we have the first clear evidence that this is not the case.”